svn commit: r361415 - in head/sys/net: . route

[Alexander V. Chernikov]

Author: melifaro
Date: Sat May 23 12:15:47 2020
New Revision: 361415
URL: https://svnweb.freebsd.org/changeset/base/361415

Log:
  Remove refcounting from rtentry.
  
  After making rtentry reclamation backed by epoch(9) in r361409, there is
   no reason in keeping reference counting code.
  
  Differential Revision:	https://reviews.freebsd.org/D24867

Modified:
  head/sys/net/route.c
  head/sys/net/route/route_var.h

Modified: head/sys/net/route.c
==============================================================================
--- head/sys/net/route.c	Sat May 23 12:00:46 2020	(r361414)
+++ head/sys/net/route.c	Sat May 23 12:15:47 2020	(r361415)
@@ -439,39 +439,8 @@ rtfree(struct rtentry *rt)
 
 	RT_LOCK_ASSERT(rt);
 
-	/*
-	 * The callers should use RTFREE_LOCKED() or RTFREE(), so
-	 * we should come here exactly with the last reference.
-	 */
-	RT_REMREF(rt);
-	if (rt->rt_refcnt > 0) {
-		log(LOG_DEBUG, "%s: %p has %d refs\n", __func__, rt, rt->rt_refcnt);
-		goto done;
-	}
-
-	/*
-	 * If we are no longer "up" (and ref == 0)
-	 * then we can free the resources associated
-	 * with the route.
-	 */
-	if ((rt->rt_flags & RTF_UP) == 0) {
-		if (rt->rt_nodes->rn_flags & (RNF_ACTIVE | RNF_ROOT))
-			panic("rtfree 2");
-#ifdef	DIAGNOSTIC
-		if (rt->rt_refcnt < 0) {
-			printf("rtfree: %p not freed (neg refs)\n", rt);
-			goto done;
-		}
-#endif
-		epoch_call(net_epoch_preempt, destroy_rtentry_epoch,
-		    &rt->rt_epoch_ctx);
-
-		/*
-		 * FALLTHROUGH to RT_UNLOCK() so the reporting functions
-		 * have consistent behaviour of operating on unlocked entry.
-		 */
-	}
-done:
+	epoch_call(net_epoch_preempt, destroy_rtentry_epoch,
+	    &rt->rt_epoch_ctx);
 	RT_UNLOCK(rt);
 }
 
@@ -958,7 +927,7 @@ rib_walk_del(u_int fibnum, int family, rt_filter_f_t *
 		if (report)
 			rt_routemsg(RTM_DELETE, rt, rt->rt_nhop->nh_ifp, 0,
 			    fibnum);
-		RTFREE_LOCKED(rt);
+		rtfree(rt);
 	}
 }
 
@@ -1114,7 +1083,6 @@ rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo 
 
 	rt = RNTORT(rn);
 	RT_LOCK(rt);
-	RT_ADDREF(rt);
 	rt->rt_flags &= ~RTF_UP;
 
 	*perror = 0;
@@ -1569,8 +1537,10 @@ add_route(struct rib_head *rnh, struct rt_addrinfo *in
 	}
 	RIB_WUNLOCK(rnh);
 
-	if (rt_old != NULL)
-		RT_UNLOCK(rt_old);
+	if (rt_old != NULL) {
+		rt_notifydelete(rt_old, info);
+		rtfree(rt_old);
+	}
 
 	/*
 	 * If it still failed to go into the tree,
@@ -1582,11 +1552,6 @@ add_route(struct rib_head *rnh, struct rt_addrinfo *in
 		return (EEXIST);
 	} 
 
-	if (rt_old != NULL) {
-		rt_notifydelete(rt_old, info);
-		RTFREE(rt_old);
-	}
-
 	/*
 	 * If this protocol has something to add to this then
 	 * allow it to do that as well.
@@ -1639,7 +1604,7 @@ del_route(struct rib_head *rnh, struct rt_addrinfo *in
 	if (ret_nrt)
 		*ret_nrt = rt;
 
-	RTFREE_LOCKED(rt);
+	rtfree(rt);
 
 	return (0);
 }

Modified: head/sys/net/route/route_var.h
==============================================================================
--- head/sys/net/route/route_var.h	Sat May 23 12:00:46 2020	(r361414)
+++ head/sys/net/route/route_var.h	Sat May 23 12:15:47 2020	(r361415)
@@ -143,7 +143,6 @@ struct rtentry {
 	};
 
 	int		rt_flags;	/* up/down?, host/net */
-	int		rt_refcnt;	/* # held references */
 	u_long		rt_weight;	/* absolute weight */ 
 	u_long		rt_expire;	/* lifetime for route, e.g. redirect */
 #define	rt_endzero	rt_mtx
@@ -161,36 +160,6 @@ struct rtentry {
 #define	RT_UNLOCK_COND(_rt)	do {				\
 	if (mtx_owned(&(_rt)->rt_mtx))				\
 		mtx_unlock(&(_rt)->rt_mtx);			\
-} while (0)
-
-#define	RT_ADDREF(_rt)	do {					\
-	RT_LOCK_ASSERT(_rt);					\
-	KASSERT((_rt)->rt_refcnt >= 0,				\
-		("negative refcnt %d", (_rt)->rt_refcnt));	\
-	(_rt)->rt_refcnt++;					\
-} while (0)
-
-#define	RT_REMREF(_rt)	do {					\
-	RT_LOCK_ASSERT(_rt);					\
-	KASSERT((_rt)->rt_refcnt > 0,				\
-		("bogus refcnt %d", (_rt)->rt_refcnt));	\
-	(_rt)->rt_refcnt--;					\
-} while (0)
-
-#define	RTFREE_LOCKED(_rt) do {					\
-	if ((_rt)->rt_refcnt <= 1)				\
-		rtfree(_rt);					\
-	else {							\
-		RT_REMREF(_rt);					\
-		RT_UNLOCK(_rt);					\
-	}							\
-	/* guard against invalid refs */			\
-	_rt = 0;						\
-} while (0)
-
-#define	RTFREE(_rt) do {					\
-	RT_LOCK(_rt);						\
-	RTFREE_LOCKED(_rt);					\
 } while (0)
 
 /*